The present invention relates generally to the field of electrical insulating systems. More particularly, the invention relates to a novel technique for insulating conductors, such as windings in electric motors and similar machines.
Many applications exist for electrical conductors and insulating systems for such conductors. Insulating systems typically vary widely in configuration and application, depending upon such factors as the voltage levels of the applications, anticipated current loads, constraints and concerns regarding installation, and so forth. In insulating systems for conductors such as those found in windings of electric motors, generators, dynamos, and similar machines, both manual and semi-automated insulation techniques have been proposed and are presently in use.
In electric motor winding environments, for example, conductors are electrically insulated from one another, typically at ends of a stator or rotor. Where possible, pre-assembled or prefabricated insulators may be applied to the conductors, such as in the form of sleeves or bonded tape. Where higher voltage ratings arc needed, multiple layers of the insulators may be employed. The layers typically include resin disposed between the multiple layers, rendering the sleeves relatively stiff and resistant to bending. While such stiffness may not pose significant problems for certain applications, other applications, particularly for larger conductors, result in breakage, cracking, and other degradation of the insulation sleeves.
In many applications, the degradation of insulation can lead to significant drawbacks and even premature damage or failure of the associated conductors and machine. In general, it is advantageous to provide the optimal dielectric path between the conductor and surrounding conductors to optimize the insulation capabilities. However, where cracks or breaks occur in the insulating sleeves, new paths are defined which will typically be less optimal then the original paths provided by the insulating material.
In addition to the foregoing drawbacks, conventional insulating systems may require expensive hand taping, or costly materials. Known insulating sleeves such as mylar, aramid fibers, silicon and acrylics, for example, are used only to limited satisfaction. Acrylics, for example, can be expensive and may not be suitable for higher voltages. Silicone sleeves suffer from drawbacks including a limited ability to provide sealing against water penetration.
There is, therefore, a need at present for an improved insulating system for conductors which addresses such drawbacks. There is, at present, a particular need for an insulating system which can be adapted for a variety of voltage ratings and conductor sizes, while providing flexibility during the assembly process to avoid cracking or breaking of the insulation material.